Limit on human embryo research should be extended to 28 days, says UK regulator

Exclusive: Experts say increasing law from 14 days could lead to breakthroughs in understanding of miscarriages

The 14-day limit for human embryo research should be extended to 28 days, the fertility regulator has recommended in a move that could pave the way for breakthroughs in understanding the causes of miscarriages and heart defects.

If adopted in law, this would permit scientists to cultivate embryos to the equivalent of 28 days of development for the first time, allowing them to study a crucial “black box” period. They say this could help uncover the origins, and develop new screening tools, for recurrent miscarriages and severe conditions such as spina bifida.